Situation Calculus Synthesis

This tool provides controller synthesis/orchestration of resource programs $\delta_i$ (where each program has a corresponding logical action theory) to realise a high-level target program (recipe). Recipes and resource programs are in the ConGolog programming language and compiled to characteristic graphs by this tool, where resource programs can be non-terminating/infinite, but recipe programs must be terminating.

Logical action theories for resource programs are given by situation calculus basic action theories, $\mathcal{D_i}$. Situation calculus is a second-order logic with equality for reasoning about actions in AI with three disjoint sorts: actions, objects, and situations. Preconditions are specified for each action (and possibly for certain configurations of compound/concurrent actions), and successor state axioms encode causal laws of changes to fluents as a result of performing actions (dynamic predicates).

This tool implements two different possible solvers/search algorithms for controller synthesis, namely: A* search (A*), and Greedy Search (GS).

Build instructions

Requirements

• CMake (>=3.26)
• Git (for submodule cloning)
• C++23 compiler (tested on Windows MSVC 19.37.32822.0)
• GraphViz for visualisation (dot must be in PATH)

Cloning & updating

Clone the repository alongside its submodules (shallow submodule cloning is optional).

git clone --recurse-submodules --shallow-submodules https://github.com/nightly/scs
git submodule update --init --recursive

During development, to correctly pull any newly added Git submodules to your local repository (git pull alone doesn't suffice):

git submodule update --recursive

CMake

Build the project using CMake or simply open it using an IDE that has CMake support.

cmake -S. -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

All of the tests can also be run with the following:

cd build
ctest --output-on-failure --verbose

Layout

• app: contains a CLI executable application.
• bench: contains all the project's benchmarks
• data: has some sample programs
• docs: contains some incomplete basic documentation/implementation notes
• examples: small example programs that can be ran/viewed
• exports: any directory marked exports gives any system/user-generated output
• external: 3rd party dependencies added as Git submodules
• src/scs: SCS library code
• tests: holds all tests & test data

Credits

• Situation calculus for controller synthesis in manufacturing systems with first-order state representation.
• Boost container hash library
• Boost flat_map, flat_set
• Planning and verification in the agent language Golog
• ankerl::unordered_dense::{map, set}